On 05/25/01, Shawn McMahon <smcmahon@eiv.com> wrote:
On Thu, May 24, 2001 at 05:49:54PM -0700, Roeland Meyer wrote:
Guys, there are more cases that may look like an open relay, but really aren't.
I don't see how you can have a false positive on an open relay test. Either it allows you to send a test email through, or it doesn't. If it does, it is by definition open.
Usually, a false positive on a relay test can happen in one of two ways: 1. you're downstream of the operators of the server that you're testing, and therefore are legitimately relaying through it (as you suggested), or 2. you don't wait to see if the message comes back. Lemme expand on #2 just a bit. Some mail servers will appear to accept all mail, and not send a 5xx response immediately. Some won't even generate a bounce message. But they also won't forward the message on to its' off-site recipient. It'll just disappear into the bit bucket. That's not an open relay, but most relay-tester scripts will just say "the message has been accepted, it must be open." -- J.D. Falk SILENCE IS FOO! <jdfalk@cybernothing.org>